Electric machines should maintain a controlled operation temperature, in order to avoid physical damage and increase efficiency during work. Normally, the air cooling systems use a fan positioned on the inner side of the deflective cover of the machine, which performs the forced convection of the air over the machine housing. The higher the airflow passage through the machine, the higher the efficiency of the cooling system. Thus, any resistance points to the free flow, such as physical obstacles or occurrence of unnecessary turbulence, should be avoided.
Currently, the fan is fixed on the rear edge of the motor shaft (4), which is already mounted on the machine; in a previous phase, the inner deflector is fixed onto the deflective cover. This way, the assembly of the deflector-cover-fan set is performed in different phases, where the deflective cover and inner deflector set is assembled last.
However, there should be a gap between the outer edge of the inner fan blades and the inner surface of the deflector, in order to avoid dragging of the edges of the fan blades on the inner surface of the deflector. This gap should compensate for all assembly tolerances of the aforementioned components. If this gap is too large, there may be some local air turbulence; if too small, there may be physical contact between the fan and the inner surface of the deflector.
In essence, this invention proposes an assembly solution for the system in order to allow more suitable positioning of the inner deflector regarding the fan, enabling the inner deflector to be mounted last on the machine, after the fan and the deflective cover are already mounted.